But the most interest aspect of infection control in the transit system was due to the
engineer William Gibbs McAdoo, responsible for the engineering of the Hudson and Manhatten Tubes (now known as PATH).
In Manhatten, the IRT used what is called "cut and cover" construction. They scooped out a channel and put a roof over it, which became the street.
McAdoo, however, had an interest in medicine, and was very concerned about tuberculosis, and the danger to commuters.